﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Configuration;
using System.Data;

namespace SqliteDAL
{
    class SqlHelper
    {
        private SqlConnection sqlCon = null;
        private SqlCommand cmd = null;
        private SqlDataReader sdr = null;
        public SqlHelper()
        {
            sqlCon = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString);
        }

        /// <summary>   
        /// 打开数据库连接   
        /// </summary>   
        /// <returns></returns>   
        private SqlConnection GetCon()
        {
            if (sqlCon.State == ConnectionState.Closed)
            {
                sqlCon.Open();
            }
            return sqlCon;
        }

        /// <summary>   
        /// 执行不带参数的增删改sql语句或存储过程   
        /// </summary>   
        /// <param name="cmdText">增删改sql语句或存储过程</param>   
        /// <param name="ct">命令类型</param>   
        /// <returns></returns>   
        public int ExecuteNonQuery(string cmdText, CommandType ct)
        {
            int rex;
            try
            {
                SqlCommand sqlcom = new SqlCommand(cmdText, GetCon());
                sqlcom.CommandType = ct;
                rex = sqlcom.ExecuteNonQuery();
            }
            catch (Exception ex)
            { 
                throw ex;
            }
            finally
            {
                if (sqlCon.State == ConnectionState.Open)
                {
                    sqlCon.Close();
                }
            }
            return rex;
        }


        /// <summary>   
        ///  执行带参数的增删改SQL语句或存储过程   
        /// </summary>   
        /// <param name="cmdText">增删改SQL语句或存储过程</param>   
        /// <param name="ct">命令类型</param>   
        /// <returns></returns>   
        public int ExecuteNonQuery(string cmdText, SqlParameter[] paras, CommandType ct)
        {
            int res;
            using (cmd = new SqlCommand(cmdText, GetCon()))
            {
                cmd.CommandType = ct;
                cmd.Parameters.AddRange(paras);
                res = cmd.ExecuteNonQuery();
            }
            return res;
        }


        /// <summary>   
        ///  执行带参数的查询SQL语句或存储过程   
        /// </summary>   
        /// <param name="cmdText">查询SQL语句或存储过程</param>   
        /// <param name="paras">参数集合</param>   
        /// <param name="ct">命令类型</param>   
        /// <returns></returns>   
        public DataTable ExecuteQuery(string cmdText, SqlParameter[] paras, CommandType ct)
        {
            DataTable dt = new DataTable();
            cmd = new SqlCommand(cmdText, GetCon());
            cmd.CommandType = ct;
            cmd.Parameters.AddRange(paras);
            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(sdr);
            }
            return dt;
        }
        /// <summary>   
        /// 执行不带参数的查询SQL语句或存储过程   
        /// </summary>   
        /// <param name="cmdText">查询SQL语句或存储过程</param>   
        /// <param name="ct">命令类型</param>   
        /// <returns></returns>   
        public DataTable ExecuteQuery(string cmdText, CommandType ct)
        {
            DataTable dt = new DataTable();
            cmd = new SqlCommand(cmdText, GetCon());
            cmd.CommandType = ct;
            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(sdr);
            }
            return dt;
        }





    }
}
